title: Carbon source-dependent modulation of NADP-glutamate dehydrogenases in isophthalate-degrading Pseudomonas aeruginosa strain PP4, Pseudomonas strain PPD and Acinetobacter lwoffii strain ISP4.
abstract: Acinetobacter lwoffii strain ISP4 metabolizes isophthalate rapidly compared with Pseudomonas aeruginosa strain PP4 and Pseudomonas strain PPD. Isophthalate has been reported to be a potent competitive inhibitor of glutamate dehydrogenase (GDH). Exogenous supplementation of isophthalate with glutamate or alpha-ketoglutarate at 1 mM concentration caused strains PP4 and PPD to grow faster than in the presence of isophthalate alone; however, no such effect was observed in strain ISP4. When grown on isophthalate, all strains showed activity of NADP-dependent GDH (NADP-GDH), while cells grown on glucose, 2x yeast extract-tryptone broth (2YT) or glutamate showed activities of both NAD-dependent GDH (NAD-GDH) and NADP-GDH. Activity staining, inhibition and thermal stability studies indicated the carbon source-dependent presence of two (GDH(I) and GDH(II)), three (GDH(A), GDH(B) and GDH(C)) and one (GDH(P)) forms of NADP-GDH in strains PP4, PPD and ISP4, respectively. The results demonstrate the carbon source-dependent modulation of different forms of NADP-GDH in these bacterial strains. This modulation may help the efficient utilization of isophthalate as a carbon source by overcoming the inhibitory effect on GDH.
authors.affiliation: Biotechnology Group, School of Biosciences and Bioengineering, Indian Institute of Technology - Bombay, Powai, Mumbai 400 076, India.
authors.forename: C
authors.initials: C
authors.lastname: Vamsee-Krishna
authors.affiliation: Biotechnology Group, School of Biosciences and Bioengineering, Indian Institute of Technology - Bombay, Powai, Mumbai 400 076, India.
authors.forename: Prashant S
authors.initials: PS
authors.lastname: Phale
mesh_terms: D000150:Acinetobacter / Q000737:chemistry / Q000201:enzymology* / Q000378:metabolism; D001426:Bacterial Proteins / Q000737:chemistry / Q000378:metabolism*; D002244:Carbon / Q000378:metabolism*; D004795:Enzyme Stability; D018086:Glutamate Dehydrogenase (NADP+) / Q000737:chemistry / Q000378:metabolism*; D009243:NAD / Q000378:metabolism; D009249:NADP / Q000378:metabolism*; D010795:Phthalic Acids / Q000378:metabolism*; D011549:Pseudomonas / Q000737:chemistry / Q000201:enzymology* / Q000378:metabolism; D013696:Temperature
chemical_list: D001426:Bacterial Proteins; D010795:Phthalic Acids; D009243:NAD; C059768:isophthalate; D009249:NADP; D002244:Carbon; D018086:Glutamate Dehydrogenase (NADP+)